The invention is related to an balanced wire resistor for the acquisition of temperature and a process for the production of an balanced wire resistor having a first desired resistance value with a first predetermined temperature and a second desired resistance value with a second predetermined temperature.
A wire resistor of this type is used advantageously in devices for the acquisition of the temperature or the temperature change of a medium. This acquisition occurs via the value of the electrical resistance or the change of the value of the electrical resistance of the wire resistor provided in the medium. The invention is generally applicable to wire resistors.
A wire resistor in which a wound wire is connected in series to a printed layer resistor and which is balanced by changing the sheet resistivity to the required extent in a known manner, e.g. by undoing conductor trains or by additional application of conductive layers, is disclosed by DE 32 17 613 A1.
It is also known from DE 29 38 962 A1 that the cross-section of a wound wire resistor can be reduced by sand blasting, thus balancing the wire resistance. However, this balancing procedures method is only suitable for uninsulated wires with relatively large wire diameters.
In addition, a device with a measuring bridge and an unwinding device for the balancing procedures of a wound, insulated wire resistor is disclosed in DE 30 26 914 C2. A generator is capacitatively coupled to the insulated wire of the wire resistor. The generator and insulated wire represent part of the measuring bridge. The wire is unwound by means of the unwinding device from the wire resistor until the desired value of wound wire resistance has been reached.
High manufacturing costs are involved because of expensive balancing procedures when known wire resistors must have desired characteristic curves.